CN106810707B - A kind of preparation method of electrically expandable colloidal crystal thin film - Google Patents

Abstract

The invention relates to a preparation method of an electrically expandable colloidal crystal film, and the invention relates to a preparation method of a colloidal crystal film. The invention solves the problem of difficult preparation of the existing electric expansion polymer material. Methods: 1. Preparation of monodisperse polystyrene microspheres; 2. Synthesis of ferrocene derivatives; 3. Preparation of electrically expandable colloidal crystal materials to obtain electrically expandable colloidal crystal materials. The invention is used for a preparation method of electrically expandable colloidal crystal film.

Description

A kind of preparation method of electrically expandable colloidal crystal thin film

technical field

The invention relates to a preparation method of a colloidal crystal thin film.

Background technique

Colloidal crystals are inorganic or organic colloidal microspheres with a size of 100nm to several microns that self-assemble under the action of a driving force to form a two-dimensional or three-dimensional ordered structure. This ordered colloidal microsphere structure Often referred to as colloidal crystals, photonic crystals, or synthetic opal structures. Because of its excellent optical properties, colloidal crystals have become the basic material of a new generation of optoelectronic devices; they can also be used as an ideal model system for the following basic phenomena, and can be used for mechanism research on hot issues such as dissolution processes and phase transition processes; in addition, colloidal crystals themselves It can also be used as a template, perfectly integrated with evaporation and photolithography techniques, and used for the preparation of patterned photonic crystals. It is precisely because of the broad application prospects of colloidal crystals and their related derivatives that they have attracted great attention in the cross-disciplines of precise regulation, chemical modification and novel applications.

Contents of the invention

The invention aims to solve the problem of difficult preparation of the existing electric expandable polymer material, and provides a preparation method of the electrically expandable colloidal crystal film.

A preparation method of electrically expandable colloidal crystal film is carried out according to the following steps:

1. Preparation of monodisperse polystyrene microspheres:

Add ultra-pure water into the three-port reactor, turn on the condensing circulating water, and use a mechanical stirrer to stir the ultra-pure water at the same time, and heat the three-port reactor to a temperature of 50°C with a super constant temperature water bath at a speed of 300rpm-3000rpm ~100°C, then pass nitrogen into the three-port reactor to remove the oxygen in the system, add styrene into the three-port reactor, then add potassium persulfate solution with a mass percentage of 1% to 50%, and react for 12h to 48h. Obtain monodisperse polystyrene microspheres with a particle size of 200nm to 1000nm;

The volume ratio of described styrene and ultrapure water is 1:(30～100); The volume ratio of described styrene and mass percentage is 1%～50% potassium persulfate solution is 1:(0.01～0.1 );

Two, the synthesis of ferrocene derivatives:

Add anhydrous AlCl ₃ and anhydrous CH ₂ Cl ₂ into the three-necked flask, then drop the mixed solution A into the three-necked flask, after the anhydrous AlCl ₃ is dissolved, add the mixed solution B dropwise, and react at room temperature for 2h~5h , to obtain the reaction solution, then pour the reaction solution into ice water, extract the aqueous layer with CH ₂ Cl ₂ extractant for 3 times, combine the organic phases, dry with anhydrous Na ₂ SO ₄ , filter, evaporate the solvent, and recrystallize with ethanol , to obtain ferrocene derivatives;

The volume ratio of the mass of anhydrous AlCl ₃ to anhydrous CH ₂ Cl ₂ is 1g:(10-100)mL; the mass ratio of anhydrous AlCl ₃ to mixed solution A is 1g:(10 ~100) mL; the quality _of the anhydrous AlCl3 and the volume ratio of the mixed solution B is 1g: (20 ~ 80) mL;

The mixed solution A is a mixture of acetyl chloride and anhydrous CH ₂ Cl ₂ , and the volume ratio of acetyl chloride and anhydrous CH ₂ Cl ₂ in the mixed solution A is 1:(10-50);

_The mixed solution B is a mixture of ferrocene and anhydrous _CH2Cl2 , and the volume ratio of the mass of ferrocene and anhydrous _CH2Cl2 in the mixed solution B is 1g: ₍ 10-50 ) mL;

3. Preparation of electrically expandable colloidal crystal materials:

Clean the ITO with an area of 1cm×4cm, soak the cleaned ITO with a mixture of 5% to 50% hydrogen peroxide and 5% to 30% sulfuric acid for 2h to 24h, and then ultrasonically treat it for 30min to 300min, then washed with deionized water and blown dry with nitrogen to obtain the pretreated ITO, and the monodisperse polystyrene microspheres with a particle size of 200nm to 1000nm were formulated with water to form polystyrene with a mass percentage of 1% to 10%. Microsphere solution, and then ultrasonically disperse for 10min~100min to obtain polystyrene suspension, add 10mL~100mL polystyrene suspension dropwise on the pretreated ITO, and spin coater at a speed of 100rpm~1000rpm , spin coating for 10s to 100s to obtain a colloidal crystal template, and ultrasonically dissolve the ferrocene derivative with ethanol to obtain a ferrocene derivative solution with a mass percentage of 1% to 10%. ～10% solution of ferrocene derivatives is added dropwise on the colloidal crystal template, spin coating for 10s～50s under the condition that the rotation speed of the spin coater is 100rpm～300rpm, and then placed in an incubator with a temperature of 30℃～100℃ drying in medium to obtain an electrically expandable colloidal crystal material;

The volume ratio of the hydrogen peroxide with a mass percentage of 5% to 50% and the sulfuric acid with a mass percentage of 5% to 30% is 1: (3 to 5).

The beneficial effects of the present invention are: 1. The whole process is simple, without special equipment and process;

2. Because a certain amount of ferrocene solution is added to the film, the film has excellent electrochromic performance under the condition of applying an appropriate voltage, and the color changing range is wide, reaching red, yellow, blue and other multi-color discoloration, which can be widely used in biology, Chemical sensors, optoelectronic devices, etc.

The invention adopts an improved emulsion polymerization method to prepare polystyrene microspheres with good monodispersity, and then prepares them into a single-layer colloidal crystal template. Then ferrocene is used as a raw material to synthesize ferrocene derivative molecules by chemical method, which is fully dissolved in ethanol and then filled into a colloidal crystal template. After drying, an electrically expandable colloidal crystal film is obtained. When an appropriate voltage is applied, the volume of the ferrocene particle changes, the lattice structure of the colloidal crystal changes, and the photonic band gap changes, thereby affecting the color change of the entire colloidal crystal film. The method has simple process and good repeatability, and greatly broadens the application field of the colloidal crystal material.

The invention is used for a preparation method of electrically expandable colloidal crystal film.

Description of drawings

Fig. 1 is the scanning electron micrograph of the colloidal crystal template prepared in step 3 of embodiment one;

Fig. 2 is the scanning electron micrograph of the ferrocene derivative prepared in embodiment 2 step 2;

Fig. 3 is the scanning electron micrograph of the electrically expandable colloidal crystal material prepared in step 3 of embodiment two;

Fig. 4 is at the wavelength of 550nm, the transmittance changes of the pure ferrocene derivative material prepared by comparative test 1 and the electrically expandable colloidal crystal material prepared by embodiment 1 in the faded state and colored state, a is a voltage of 1V Next, the transmission spectrum in the faded state of the pure ferrocene derivative material prepared in Comparative Test 1, b is the transmission spectrum in the faded state of the electrically expandable colloidal crystal material prepared in Example 1 at a voltage of 1V, and c is the transmission spectrum in the faded state at a voltage of - Under 1V, the colored state transmission spectrum of the pure ferrocene derivative material prepared in comparative test 1, d is the colored state transmission spectrum of the electrically expandable colloidal crystal material prepared in Example 1 under a voltage of -1V;

Figure 5 is a diagram of the transmittance variation of the electrically expandable colloidal crystal material prepared in Example 2 under different voltages at a wavelength of 550nm, where 1 is 2V, 2 is 1.5V, 3 is 1V, 4 is -0.5V, and 5 is -1V, 6 is -1.5V, 7 is -2V.

Detailed ways

Embodiment 1: A method for preparing an electrically expandable colloidal crystal film in this embodiment is carried out in the following steps:

1. Preparation of monodisperse polystyrene microspheres:

Add ultra-pure water into the three-port reactor, turn on the condensing circulating water, and use a mechanical stirrer to stir the ultra-pure water at the same time, and heat the three-port reactor to a temperature of 50°C with a super constant temperature water bath at a speed of 300rpm-3000rpm ~100°C, then pass nitrogen into the three-port reactor to remove the oxygen in the system, add styrene into the three-port reactor, then add potassium persulfate solution with a mass percentage of 1% to 50%, and react for 12h to 48h. Obtain monodisperse polystyrene microspheres with a particle size of 200nm to 1000nm;

The volume ratio of described styrene and ultrapure water is 1:(30～100); The volume ratio of described styrene and mass percentage is 1%～50% potassium persulfate solution is 1:(0.01～0.1 );

Two, the synthesis of ferrocene derivatives:

Add anhydrous AlCl ₃ and anhydrous CH ₂ Cl ₂ into the three-necked flask, then drop the mixed solution A into the three-necked flask, after the anhydrous AlCl ₃ is dissolved, add the mixed solution B dropwise, and react at room temperature for 2h~5h , to obtain the reaction solution, then pour the reaction solution into ice water, extract the aqueous layer with CH ₂ Cl ₂ extractant for 3 times, combine the organic phases, dry with anhydrous Na ₂ SO ₄ , filter, evaporate the solvent, and recrystallize with ethanol , to obtain ferrocene derivatives;

The volume ratio of the mass of anhydrous AlCl ₃ to anhydrous CH ₂ Cl ₂ is 1g:(10-100)mL; the mass ratio of anhydrous AlCl ₃ to mixed solution A is 1g:(10 ~100) mL; the quality _of the anhydrous AlCl3 and the volume ratio of the mixed solution B is 1g: (20 ~ 80) mL;

The mixed solution A is a mixture of acetyl chloride and anhydrous CH ₂ Cl ₂ , and the volume ratio of acetyl chloride and anhydrous CH ₂ Cl ₂ in the mixed solution A is 1:(10-50);

_The mixed solution B is a mixture of ferrocene and anhydrous _CH2Cl2 , and the volume ratio of the mass of ferrocene and anhydrous _CH2Cl2 in the mixed solution B is 1g: ₍ 10-50 ) mL;

3. Preparation of electrically expandable colloidal crystal materials:

Clean the ITO with an area of 1cm×4cm, soak the cleaned ITO with a mixture of 5% to 50% hydrogen peroxide and 5% to 30% sulfuric acid for 2h to 24h, and then ultrasonically treat it for 30min to 300min, then washed with deionized water and blown dry with nitrogen to obtain the pretreated ITO, and the monodisperse polystyrene microspheres with a particle size of 200nm to 1000nm were formulated with water to form polystyrene with a mass percentage of 1% to 10%. Microsphere solution, and then ultrasonically disperse for 10min~100min to obtain polystyrene suspension, add 10mL~100mL polystyrene suspension dropwise on the pretreated ITO, and spin coater at a speed of 100rpm~1000rpm , spin coating for 10s to 100s to obtain a colloidal crystal template, and ultrasonically dissolve the ferrocene derivative with ethanol to obtain a ferrocene derivative solution with a mass percentage of 1% to 10%. ～10% solution of ferrocene derivatives is added dropwise on the colloidal crystal template, spin coating for 10s～50s under the condition that the rotation speed of the spin coater is 100rpm～300rpm, and then placed in an incubator with a temperature of 30℃～100℃ drying in medium to obtain an electrically expandable colloidal crystal material;

The volume ratio of the hydrogen peroxide with a mass percentage of 5% to 50% and the sulfuric acid with a mass percentage of 5% to 30% is 1: (3 to 5).

The ferrocene, anhydrous AlCl ₃ and anhydrous CH ₂ Cl ₂ selected in this specific embodiment are all dehydrated by zeolite and vacuum-distilled to remove impurities, and sealed for use.

The beneficial effects of this embodiment are: 1. The whole process is simple, without special equipment and process;

2. Because a certain amount of ferrocene solution is added to the film, the film has excellent electrochromic performance under the condition of applying an appropriate voltage, and the color changing range is wide, reaching red, yellow, blue and other multi-color discoloration, which can be widely used in biology, Chemical sensors, optoelectronic devices, etc.

The invention adopts an improved emulsion polymerization method to prepare polystyrene microspheres with good monodispersity, and then prepares them into a single-layer colloidal crystal template. Then ferrocene is used as a raw material to synthesize ferrocene derivative molecules by chemical method, which is fully dissolved in ethanol and then filled into a colloidal crystal template. After drying, an electrically expandable colloidal crystal film is obtained. When an appropriate voltage is applied, the volume of the ferrocene particle changes, the lattice structure of the colloidal crystal changes, and the photonic band gap changes, thereby affecting the color change of the entire colloidal crystal film. The method has simple process and good repeatability, and greatly broadens the application field of the colloidal crystal material.

Embodiment 2: The difference between this embodiment and Embodiment 1 is that the volume ratio of styrene and ultrapure water described in step 1 is 1:(50-100). Others are the same as in the first embodiment.

Specific embodiment three: what this embodiment is different from one of specific embodiment one or two is: the volume ratio of the potassium persulfate solution of 1%～50% is 1:( 0.02～0.1). Others are the same as in the first or second embodiment.

Embodiment 4: This embodiment differs from Embodiments 1 to 3 in that the volume ratio of the mass of anhydrous AlCl ₃ described in step 2 to anhydrous CH ₂ Cl ₂ is 1 g: (20-100) mL. Others are the same as the specific embodiments 1 to 3.

Embodiment 5: This embodiment differs from Embodiment 1 to Embodiment 4 in that the volume ratio of the mass of anhydrous AlCl ₃ described in step 2 to the mixed solution A is 1 g:(20-100) mL. Others are the same as the specific embodiments 1 to 4.

Embodiment 6: This embodiment differs from Embodiment 1 to Embodiment 5 in that the volume ratio of the mass of anhydrous AlCl ₃ described in step 2 to the mixed solution B is 1 g:(30-80) mL. Others are the same as those in Embodiments 1 to 5.

Embodiment 7: The difference between this embodiment and one of Embodiments 1 to 6 is that the mixed solution A described in step 2 is a mixture of acetyl chloride and anhydrous CH ₂ Cl ₂ , and the mixed solution A in the The volume ratio of acetyl chloride to anhydrous CH ₂ Cl ₂ is 1:(20~50). Others are the same as those in Embodiments 1 to 6.

Embodiment 8: The difference between this embodiment and one of Embodiments 1 to 7 is that the mixed solution B described in step 2 is a mixture of ferrocene and anhydrous CH ₂ Cl ₂ , and the mixed solution B The mass ratio of ferrocene to anhydrous CH ₂ Cl ₂ is 1g:(20～50)mL. Others are the same as those in Embodiments 1 to 7.

Specific embodiment nine: the difference between this embodiment and one of the specific embodiments one to eight is: the volume ratio of the hydrogen peroxide with the mass percentage of 5% to 50% and the sulfuric acid with the mass percentage of 5% to 30% described in step three It is 1:(3.5～5). Others are the same as those in Embodiments 1 to 8.

Embodiment 10: This embodiment differs from Embodiment 1 to Embodiment 9 in that: In step 3, 20 μL to 500 μL of a ferrocene derivative solution with a mass percentage of 1% to 10% is dropped on the colloidal crystal template. Others are the same as the specific embodiments 1 to 9.

The beneficial effects of this embodiment are:

Adopt the following examples to verify the beneficial effects of the present invention:

Embodiment one:

A preparation method of electrically expandable colloidal crystal film is carried out according to the following steps:

1. Preparation of monodisperse polystyrene microspheres:

Add ultra-pure water into the three-port reactor, turn on the condensing circulating water, and use a mechanical stirrer to stir the ultra-pure water at the same time, and heat the three-port reactor to a temperature of 50°C with a super constant temperature water bath at a speed of 300 rpm, then Pass nitrogen into the three-port reactor to remove the oxygen in the system, add styrene to the three-port reactor, and then add a 10% potassium persulfate solution by mass percentage, and react for 12 hours to obtain a monodisperse polystyrene with a particle size of 210nm. Ethylene microspheres;

The volume ratio of described styrene and ultrapure water is 1:30; The volume ratio of described styrene and mass percentage is 10% potassium persulfate solution is 1:0.01;

Two, the synthesis of ferrocene derivatives:

Add anhydrous AlCl ₃ and anhydrous CH ₂ Cl ₂ into the three-necked flask, then drop the mixed solution A into the three-necked flask, after the anhydrous AlCl ₃ is dissolved, add the mixed solution B dropwise, and react at room temperature for 2 hours to obtain reaction solution, then the reaction solution was poured into ice water, the aqueous layer was extracted 3 times with a CH ₂ Cl ₂ extraction agent with a single dosage of 40 mL, the organic phases were combined, dried with anhydrous Na ₂ SO ₄ , filtered, and the solvent was evaporated, Recrystallize with ethanol to obtain ferrocene derivatives;

The volume ratio of the mass of the anhydrous AlCl ₃ to the anhydrous CH ₂ Cl ₂ is 1g:10mL; the mass of the anhydrous AlCl ₃ and the volume ratio of the mixed solution A is 1g:10mL; the anhydrous The volume ratio _of the quality of AlCl to the mixed solution B is 1g:20mL;

The mixed solution A is a mixture of acetyl chloride and anhydrous CH ₂ Cl ₂ , and the volume ratio of acetyl chloride and anhydrous CH ₂ Cl ₂ in the mixed solution A is 1:10;

The mixed solution B is a mixture of ferrocene and anhydrous CH ₂ Cl ₂ , and the volume ratio of the mass of ferrocene in the mixed solution B to the anhydrous CH ₂ Cl ₂ is 1g:10mL;

3. Preparation of electrically expandable colloidal crystal materials:

Clean the ITO with an area of 1cm×4cm, soak the cleaned ITO with a mixture of 10% hydrogen peroxide and 20% sulfuric acid for 24 hours, then ultrasonically treat it for 30 minutes, then wash it with deionized water and blow it with nitrogen. Blow dry to obtain pretreated ITO, prepare monodisperse polystyrene microspheres with a particle size of 210nm with water to make a polystyrene microsphere solution with a mass percentage of 1%, and then ultrasonically disperse for 10 minutes to obtain a polystyrene suspension , 10mL polystyrene suspension was added dropwise on the pretreated ITO, and spin-coated for 10s under the condition of a spin-coater rotating speed of 100rpm to obtain a colloidal crystal template, and the ferrocene derivative was ultrasonically dissolved in ethanol , to obtain a 1% ferrocene derivative solution by mass percentage, drop 20 μL of a 1% ferrocene derivative solution on the colloidal crystal template, and spin-coat 10s, and then placed in an incubator at a temperature of 30°C to dry to obtain an electrically expandable colloidal crystal material;

The volume ratio of the hydrogen peroxide having a mass percentage of 10% to the sulfuric acid having a mass percentage of 20% is 1:3.

The ferrocene derivative prepared in Step 2 of this example is a red needle crystal with a yield of 77.8% and m.p.126°C.

Comparative test one:

One, the synthesis of ferrocene derivatives:

Add anhydrous AlCl ₃ and anhydrous CH ₂ Cl ₂ into the three-necked flask, then drop the mixed solution A into the three-necked flask, after the anhydrous AlCl ₃ is dissolved, add the mixed solution B dropwise, and react at room temperature for 2 hours to obtain reaction solution, then the reaction solution was poured into ice water, the aqueous layer was extracted 3 times with a CH ₂ Cl ₂ extraction agent with a single dosage of 40 mL, the organic phases were combined, dried with anhydrous Na ₂ SO ₄ , filtered, and the solvent was evaporated, Recrystallize with ethanol to obtain ferrocene derivatives;

The volume ratio of the mass of the anhydrous AlCl ₃ to the anhydrous CH ₂ Cl ₂ is 1g:10mL; the mass of the anhydrous AlCl ₃ and the volume ratio of the mixed solution A is 1g:10mL; the anhydrous The volume ratio _of the quality of AlCl to the mixed solution B is 1g:20mL;

The mixed solution A is a mixture of acetyl chloride and anhydrous CH ₂ Cl ₂ , and the volume ratio of acetyl chloride and anhydrous CH ₂ Cl ₂ in the mixed solution A is 1:10;

The mixed solution B is a mixture of ferrocene and anhydrous CH ₂ Cl ₂ , and the volume ratio of the mass of ferrocene in the mixed solution B to the anhydrous CH ₂ Cl ₂ is 1g:10mL;

2. Preparation of electrically expandable colloidal crystal materials:

Clean the ITO with an area of 1cm×4cm, soak the cleaned ITO with a mixture of 10% hydrogen peroxide and 20% sulfuric acid for 24 hours, then ultrasonically treat it for 30 minutes, then wash it with deionized water and blow it with nitrogen. Blow dry to obtain the pretreated ITO, dissolve the ferrocene derivatives with ethanol ultrasonically to obtain a 1% ferrocene derivative solution by mass percentage, and 20 μL of the 1% ferrocene derivative solution Add it dropwise on the pretreated ITO, spin-coat it for 10s under the condition that the rotation speed of the spin-coater is 100rpm, and then place it in an incubator at a temperature of 30°C to dry to obtain a pure ferrocene derivative material;

The volume ratio of the hydrogen peroxide having a mass percentage of 10% to the sulfuric acid having a mass percentage of 20% is 1:3.

The electrochemical performance was tested using a three-electrode system. Shanghai Chenhua 600 electrochemical workstation was used for the test, with polycarbonate as the solvent and lithium perchlorate as the solute, an electrolyte solution with a concentration of 0.01mol/L was prepared, and the pure ferrocene derivative material prepared in comparative test 1 or The electrically expandable colloidal crystal material prepared in Example 1 was used as the working electrode, the platinum wire was used as the counter electrode, and the silver wire was used as the reference electrode, and the transmittance variation curve was tested. Through a large number of preliminary experiments, the selected electrochemical window is -2.5V ~ 2.5V, and the pure ferrocene derivative material prepared in comparative experiment 1 and the electrically expanded colloidal crystal material prepared in Example 1 are tested respectively in the colored state and faded state. The change of transmittance at a wavelength of 550nm. When the electrochemical window is -1V and 1V, respectively test the pure ferrocene derivative material prepared by comparative test 1 and the electrically expanded colloidal crystal material prepared by embodiment 1 in the colored state and faded state at a wavelength of 550nm. changes, as shown in Figure 4.

Embodiment two:

A preparation method of electrically expandable colloidal crystal film is carried out according to the following steps:

1. Preparation of monodisperse polystyrene microspheres:

Add ultra-pure water into the three-port reactor, turn on the condensing circulating water, and use a mechanical stirrer to stir the ultra-pure water at the same time, and heat the three-port reactor to a temperature of 80°C with a super constant temperature water bath at a speed of 3000 rpm, and then Pass nitrogen into the three-port reactor to remove the oxygen in the system, add styrene to the three-port reactor, and then add a 10% by mass percent potassium persulfate solution, react for 48 hours, and obtain a monodisperse polystyrene with a particle size of 230nm Ethylene microspheres;

The volume ratio of described styrene and ultrapure water is 1:100; The volume ratio of described styrene and mass percentage is 10% potassium persulfate solution is 1:0.1;

Two, the synthesis of ferrocene derivatives:

Add anhydrous AlCl ₃ and anhydrous CH ₂ Cl ₂ into the three-necked flask, then drop the mixed solution A into the three-necked flask, after the anhydrous AlCl ₃ is dissolved, add the mixed solution B dropwise, and react at room temperature for 2 hours to obtain reaction solution, then the reaction solution was poured into ice water, the aqueous layer was extracted 3 times with a CH ₂ Cl ₂ extraction agent with a single dosage of 40 mL, the organic phases were combined, dried with anhydrous Na ₂ SO ₄ , filtered, and the solvent was evaporated, Recrystallize with ethanol to obtain ferrocene derivatives;

The volume ratio of the mass of the anhydrous AlCl ₃ to the anhydrous CH ₂ Cl ₂ is 1g:100mL; the mass of the anhydrous AlCl ₃ and the volume ratio of the mixed solution A is 1g:100mL; the anhydrous The volume ratio _of the mass of AlCl to the mixed solution B is 1g:80mL;

The mixed solution A is a mixture of acetyl chloride and anhydrous CH ₂ Cl ₂ , and the volume ratio of acetyl chloride and anhydrous CH ₂ Cl ₂ in the mixed solution A is 1:50;

The mixed solution B is a mixture of ferrocene and anhydrous CH ₂ Cl ₂ , and the volume ratio of the mass of ferrocene in the mixed solution B to anhydrous CH ₂ Cl ₂ is 1g:50mL;

3. Preparation of electrically expandable colloidal crystal materials:

Clean the ITO with an area of 1cm×4cm, soak the cleaned ITO with a mixture of 20% hydrogen peroxide and 15% sulfuric acid for 12h, and then ultrasonically treat it for 50min, then wash it with deionized water and blow it with nitrogen. Blow dry to obtain pretreated ITO, and prepare monodisperse polystyrene microspheres with a particle size of 230nm with water to make a 10% polystyrene microsphere solution by mass percentage, and then ultrasonically disperse for 100min to obtain a polystyrene suspension , 100mL polystyrene suspension was added dropwise on the pretreated ITO, and spin-coated for 100s under the condition of a spin-coater rotating speed of 1000rpm to obtain a colloidal crystal template, and the ferrocene derivative was ultrasonically dissolved in ethanol , to obtain a 10% mass percent ferrocene derivative solution, 50 μL of a 10% mass percent ferrocene derivative solution is dropped on the colloidal crystal template, and spin coating 50s, and then placed in an incubator at a temperature of 30°C to dry to obtain an electrically expandable colloidal crystal material;

The volume ratio of the hydrogen peroxide having a mass percentage of 20% to the sulfuric acid having a mass percentage of 15% is 1:5.

The ferrocene derivative prepared in Step 2 of this example is a red needle-like crystal with a yield of 77.8% and m.p.126-128°C.

The electrochemical performance was tested using a three-electrode system. Shanghai Chenhua 600 electrochemical workstation was used for the test, with polycarbonate as the solvent and lithium perchlorate as the solute, an electrolyte solution with a concentration of 0.01mol/L was prepared, and the electrically expandable colloidal crystal material prepared in Example 2 was used as the working electrode. The platinum wire is the counter electrode, the silver wire is the reference electrode, and the transmittance variation curve is tested. Through a large number of preliminary experiments, the selected electrochemical window is -2V ~ 2V, and the change of the transmittance at the wavelength of 550nm of the colored state and the faded state of the electrically expandable colloidal crystal material prepared in Example 2 was tested respectively. The test results are shown in Figure 5 shown.

FIG. 1 is a scanning electron microscope image of the colloidal crystal template prepared in Step 3 of Example 1; it can be seen from the figure that the obtained colloidal crystal template has a face-centered cubic structure with a high degree of order.

Fig. 2 is a scanning electron microscope image of the ferrocene derivative prepared in step 2 of Example 2; it can be seen from the figure that the pure ferrocene derivative film has a compact structure and no obvious nanostructure.

Fig. 3 is the scanning electron micrograph of the electrically expandable colloidal crystal material prepared in embodiment two steps three; As can be seen from the figure, the ferrocene derivative material is attached to the polystyrene microsphere surface, and under the effect of the ferrocene derivative, The distance between the polystyrene microspheres becomes larger, and the whole material has a distinct nanostructure.

Fig. 4 is at the wavelength of 550nm, the transmittance changes of the pure ferrocene derivative material prepared by comparative test 1 and the electrically expandable colloidal crystal material prepared by embodiment 1 in the faded state and the colored state, and a is a voltage of 1V Next, the transmission spectrum in the faded state of the pure ferrocene derivative material prepared in Comparative Test 1, b is the transmission spectrum in the faded state of the electrically expandable colloidal crystal material prepared in Example 1 at a voltage of 1V, and c is the transmission spectrum in the faded state at a voltage of - Under 1V, the colored state transmission spectrum of the pure ferrocene derivative material prepared in Comparative Test 1, d is the colored state transmission spectrum of the electrically expandable colloidal crystal material prepared in Example 1 under the voltage of -1V. It can be seen from the figure that the transmittance change of the electrically expanded colloidal crystal material reaches 38%. It can be seen that under the stimulation of the electric field, the ferrocene derivative undergoes volume expansion, which leads to the shift of the forbidden band position of the colloidal crystal, and the color of the sample changes. , the film transmittance changes significantly.

Figure 5 is a diagram of the transmittance variation of the electrically expandable colloidal crystal material prepared in Example 2 under different voltages at a wavelength of 550nm, where 1 is 2V, 2 is 1.5V, 3 is 1V, 4 is -0.5V, and 5 is -1V, 6 is -1.5V, 7 is -2V. It can be seen from the figure that the transmittance of the sample changes significantly when the electrochemical window is -2V to 2V. When the direction of the electric field is from positive to negative, the transmittance of the sample decreases and the color gradually deepens, indicating that the electroexpandable material is cathodically colored.

Claims (10)

1. a preparation method of electrically expandable colloidal crystal film, is characterized in that, carries out according to the following steps: 1. Preparation of monodisperse polystyrene microspheres: Add ultra-pure water into the three-port reactor, turn on the condensing circulating water, and use a mechanical stirrer to stir the ultra-pure water at the same time, and heat the three-port reactor to a temperature of 50°C with a super constant temperature water bath at a speed of 300rpm-3000rpm ~100°C, then pass nitrogen into the three-port reactor to remove the oxygen in the system, add styrene into the three-port reactor, then add potassium persulfate solution with a mass percentage of 1% to 50%, and react for 12h to 48h. Obtain monodisperse polystyrene microspheres with a particle size of 200nm to 1000nm; The volume ratio of described styrene and ultrapure water is 1:(30～100); The volume ratio of described styrene and mass percentage is 1%～50% potassium persulfate solution is 1:(0.01～0.1 ); Two, the synthesis of ferrocene derivatives: Add anhydrous AlCl ₃ and anhydrous CH ₂ Cl ₂ into the three-necked flask, then drop the mixed solution A into the three-necked flask, after the anhydrous AlCl ₃ is dissolved, add the mixed solution B dropwise, and react at room temperature for 2h~5h , to obtain the reaction solution, then pour the reaction solution into ice water, extract the aqueous layer with CH ₂ Cl ₂ extractant for 3 times, combine the organic phases, dry with anhydrous Na ₂ SO ₄ , filter, evaporate the solvent, and recrystallize with ethanol , to obtain ferrocene derivatives; The volume ratio of the mass of anhydrous AlCl ₃ to anhydrous CH ₂ Cl ₂ is 1g:(10-100)mL; the mass ratio of anhydrous AlCl ₃ to mixed solution A is 1g:(10 ~100) mL; the quality _of the anhydrous AlCl3 and the volume ratio of the mixed solution B is 1g: (20 ~ 80) mL; The mixed solution A is a mixture of acetyl chloride and anhydrous CH ₂ Cl ₂ , and the volume ratio of acetyl chloride and anhydrous CH ₂ Cl ₂ in the mixed solution A is 1:(10-50); The mixed solution B is a mixture of ferrocene and anhydrous CH ₂ Cl ₂ , and the volume ratio of the mass of ferrocene in the mixed solution B to anhydrous CH ₂ Cl ₂ is 1g:(10-50 ) mL; 3. Preparation of electrically expandable colloidal crystal materials: Clean the ITO with an area of 1cm×4cm, soak the cleaned ITO with a mixture of 5% to 50% hydrogen peroxide and 5% to 30% sulfuric acid for 2h to 24h, and then ultrasonically treat it for 30min to 300min, then washed with deionized water and blown dry with nitrogen to obtain the pretreated ITO, and the monodisperse polystyrene microspheres with a particle size of 200nm to 1000nm were formulated with water to form polystyrene with a mass percentage of 1% to 10%. Microsphere solution, and then ultrasonically disperse for 10min~100min to obtain polystyrene suspension, add 10mL~100mL polystyrene suspension dropwise on the pretreated ITO, and spin coater at a speed of 100rpm~1000rpm , spin coating for 10s to 100s to obtain a colloidal crystal template, and ultrasonically dissolve the ferrocene derivative with ethanol to obtain a ferrocene derivative solution with a mass percentage of 1% to 10%. ～10% solution of ferrocene derivatives is added dropwise on the colloidal crystal template, spin coating for 10s～50s under the condition that the rotation speed of the spin coater is 100rpm～300rpm, and then placed in an incubator with a temperature of 30℃～100℃ dry in medium to obtain an electrically expandable colloidal crystal film; The volume ratio of the hydrogen peroxide with a mass percentage of 5% to 50% and the sulfuric acid with a mass percentage of 5% to 30% is 1: (3 to 5). 2. A method for preparing an electrically expandable colloidal crystal film according to claim 1, characterized in that the volume ratio of styrene and ultrapure water described in step 1 is 1:(50-100). 3. the preparation method of a kind of electrically expandable colloidal crystal thin film according to claim 1, it is characterized in that the styrene described in step 1 and mass percent are that the volume ratio of the potassium persulfate solution of 1%～50% is 1: (0.02～0.1). 4. a kind of preparation method of electrically expandable colloidal crystal thin film according to claim 1, it is characterized in that the quality of anhydrous AlCl described in step ₂ and the volume ratio of anhydrous CH ₂ Cl ₂ are 1g:( 20-100) mL. 5. A kind of preparation method of electrically expandable colloidal crystal thin film according to claim 1, it is characterized in that the anhydrous AlCl described in step ₂ The quality and the volume ratio of mixed solution A are 1g:(20～100 ) mL. 6. A kind of preparation method of electrically expandable colloidal crystal film according to claim 1, it is characterized in that the anhydrous AlCl described in step ₂ The quality and the volume ratio of mixed solution B are 1g:(30～80 ) mL. 7. A method for preparing an electrically expandable colloidal crystal film according to claim 1, characterized in that the mixed solution A described in step 2 is a mixture of acetyl chloride and anhydrous CH ₂ Cl ₂ , and said The volume ratio of acetyl chloride to anhydrous CH ₂ Cl ₂ in the mixture A is 1:(20-50). 8. A method for preparing an electrically expandable colloidal crystal film according to claim 1, characterized in that the mixed solution B described in step 2 is a mixture of ferrocene and anhydrous CH ₂ Cl ₂ , and the The mass ratio of ferrocene to anhydrous CH ₂ Cl ₂ in the mixed solution B is 1g:(20-50)mL. 9. A method for preparing an electrically expandable colloidal crystal film according to claim 1, characterized in that the hydrogen peroxide with a mass percentage of 5% to 50% and the hydrogen peroxide with a mass percentage of 5% to 30% are described in step 3. The volume ratio of sulfuric acid is 1:(3.5~5). 10. A method for preparing an electrically expandable colloidal crystal film according to claim 1, characterized in that in step 3, 20 μL to 500 μL of a ferrocene derivative solution with a mass percentage of 1% to 10% is added dropwise to the colloid on the crystal template.